White streaks on chest x-ray?

My grandfather went to the doctor today for a cough that he couldn't get to walk away... they did a chest x-ray and told him there were white streaks on his heart (in the x-ray). I'm not a doctor and hold no idea what this could be. Could it have anything to do next to a staph infection he got from the hospital? He's going back for more test tomorrow.

I don't need any answers like "I'm sure he'll be fine... blah blah blah..." I'm looking for an answer from someone who KNOWS what they're chitchat about (someone in a medical profession) or someone that's be through the same thing. Thanks!